Exactitud del Xiaomi Mi Band 4 para contabilizar pasos en adultos con enfermedades respiratorias crónicas. Estudio de concordancia.

Introduction: Xiaomi Mi Band 4 (XMB4) has been shown to be accurate to measure steps in healthy subjects, but has not been studied in patients with chronic respiratory diseases (CRD). Objectives: To evaluate the accuracy of the XMB4 to quantify steps walked in patients with CRD. Secondarily, evaluate its feasibility and usability. Materials and methods: Agreement study compared the XMB4 data with the video (reference test). Adults aged 18 years or older with various CRD were included and those with cognitive impairment, osteoarticular and/or cardiovascular limitations that prevented walking were excluded. We conducted a convenience sampling of patients participating in a pulmonary rehabilitation program. Outcome measures studied included number of steps, distance and time walked, walking speed, feasibility and usability. Each participant performed five walks (5, 10 and 30 meters, and 5 minutes at a slow and fast pace). To test statistical equivalence we need to include 33 patients and use the confidence interval method with an equivalence zone of ±15%. Results: 33 patients were included, 64% women, with a median (P25-75) age of 64.9 (55.8 to 70.2) years. The steps recorded by the XMB4 were equivalent to those of the video in the different walks, except for the 5-meter walk. The steps were underestimated with a measurement error of less than 15%. Conclusions: XMB4 has acceptable accuracy for measuring steps in patients with CRD except for very short walks, it is feasible and easy to use.